Principles Of Oncological Surgery Flashcards
Why is it important to biopsy as large a section of tissue as possible?
Bigger piece of tissue + better chance of correct diagnosis
Smaller bits of tissue increases risk of sampling error
What are the advantages of surgical tumour resection?
Immediate cure Not carcinogenic No toxic effects Not immunosuppressive Better for large masses
What are the disadvantages of surgical excision?
Local cure only
Change in cosmesis
Change in function
What steps do you need to take to plan surgical excision?
histologically diagnosis
Assess extent of local disease
Look for presence of local or distant metastasis
Assess the nutritional status of the patient
What is the best method to assess the presence of local or distant metastasis?
CT
Why is it important to assess the nutritional status of the patient before sx?
May want to build nutritional management into treatment plan e.g. feeding tube
When in the course of disease would you aim to surgically excise a tumour ?
Early
Which surgery has the best chance of success?
Why?
The FIRST ONE
Anatomy gets distorted by the first sx
What should not influence decisions relating to margins?
Concerns regarding closure
In practice?
Where are the most active and invasive parts of a tumour located?
PERIPHERY
When should biopsy be performed?
If the treatment plan would be changed
- type of tx
- extent of tx
If owner’s decision would be changed
- tumour type/grade, clinical stage, prognosis
If lesion in difficult area - head + neck, distal limb
When might biopsy not be indicated?
Mass in thorax
- DDx : primary tumour, lung lobe abscess, fungal granuloma
- all tx with excisional surgery
Solitary pulmonary nodule
- excisional biopsy - curative (of primary) + diagnostic -
Don’t need to know prior to sx
Which has a better survival time: an osteosarcoma or a chondrosarcoma?
CHONDROSARCOMA - 3-4 years
Osteosarcoma ~6 months
When would biopsy not be indicated?
Treatment plan would not be changed
- mammary mass excisions
- single large lung mass lobectomy
No change in owner’s willingness to treat
- chest wall sarcoma resection
Biopsy is as difficult as sx
- CNS mass lesions, thyroid tumours, small intestine tumours
Why might you not biopsy thyroid tumours?
Very vascular
What are the types of biopsy?
Needle
Incisional
Excisional
What are the types of needle biopsy?
FNA
Core - tru-cut
What limitations are associated with FNAs?
False negatives common
What are FNAs good at diagnosing?
MCT, lymphoma
What issue is associated with core/tru-cut biopsy?
Might just get a lot of necrotic tissue.
What are the types of incisional biopsy?
Surgical
Grab biopsy
Punch biopsy
What should you bear in mind when performing an incisional biopsy?
Biopsy in a way that won’t compromise excision surgery later
E.g. biopsy jaw tumours through oral cavity
Why should you punch biopsy at the edge of a lesion?
To get the transitional zone
How can you reduce contamination when excising a tumour?
- Avoid entering the pseudocapsule (contains tumour cells)
- Manipulate tumour gently (use atraumatic forceps)
- Isolate tumour from body cavity
- Resect adhesions between tumour and normal tissue
- Lavage the surgery site - removes blood, necrotic tissue, foreign material
- Change gloves and instruments
How should you manage the blood vessels during sx?
Reduce blood flow to reduce embolic spread
VEINS - prevents venous emboli (still spread via lymphatic
ARTERIES - prevents haemorrhage, prevents organ congestion, reduced arterial supply = reduced venous outflow
How can you tell if metastasis to a LN has occurred?
Can ONLY tell for certain by excising the whole LN and using microscopy
When should you remove a regional LN?
LN is positive for tumour and not fixed to another tissue
LN is grossly abnormal at sx
LN intimately attached to excised tissue
Also if associated with therapeutic benefit
When should you NOT remove a regional LN?
If LN fixed to critical adjacent tissue
- e.g. Bronchial LNs closely associated with vessels
If uncertain as to whether positive for tumour
(then biopsy indicated)
What are the types of local metastasis that may surround a tumour?
Satellite metastasis (closer to tumour)
Skip metastasis
Finger like projection
What are the aims of margins of excision?
Removal of the tumour and a margin of normal tissue
What are typical margins taken?
3-5 cm around,
1 fascial plane deep
What is the pseudocapsule?
A zone of compressed tissue around the tumour.
Contains viable tumour cells
DO NOT ENTER WHEN EXCISING
When would you consider ‘shelling out’ a tumour?
Very large lipomas between muscle bellies
What is local excision?
Tumour removed through the natural capsule or immediate boundaries
When is local excision indicated?
Benign tumours and NO local invasion
E.g. lipoma, histiocytoma, sebaceous adenoma
To preserve adjacent tissue
E.g. thyroid adenoma or CNS
When is local excision contraindicated?
Local invasion
Malignancy
What is wide local excision?
Tumour removed with substantial margin of normal tissue
When is wide local excision indicated?
Benign tumours / local invasion
Malignancy/ limited local invasion
What margins would be indicated for a SCC or benign oral tumour?
1cm
What margins would be indicated for a MCT or ST sarcoma?
2-3cm
When is wide local excision contraindicated?
More invasive malignancies
Higher grade tumours
What is radical excision?
Margins extend into fascial planes undisturbed by tumour growth
When is radical excision indicated?
Malignancy
Local invasion
What are the four types of radical excision?
Radical local
Compartmental
Muscle group excision
Amputation
What is radical local excision?
Tumour removed with extensive margins of tissue including one or two fascial planes beyond gross tumour
When might radical local excision be indicated?
Invasive sarcoma of the abdominal or chest wall
Invasive carcinoma of nasal plan up
Invasive tumours involving eyelids
Invasive orbital/periorbital tumours
What is compartmental excision?
Tumour is removed in an intact anatomic compartment
E.g. tumour inside muscle belly —> excise muscle
When is amputation indicated?
Large tumours
If radical excision impairs function - e.g. bone/joint
Management of recurrences - disturbed fascial planes
